http://asm.objectweb.org/asm-tree/: A very small and fast Java bytecode manipulation framework (ObjectWeb)
  • Eric Bruneton
  • Eugene Kuleshov
  • Remi Forax 
ASM: a very small and fast Java bytecode manipulation framework
Copyright (c) 2000-2011 INRIA, France Telecom
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
   notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
   notice, this list of conditions and the following disclaimer in the
   documentation and/or other materials provided with the distribution.
3. Neither the name of the copyright holders nor the names of its
   contributors may be used to endorse or promote products derived from
   this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
THE POSSIBILITY OF SUCH DAMAGE.

/***
 * ASM: a very small and fast Java bytecode manipulation framework
 * Copyright (c) 2000-2011 INRIA, France Telecom
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holders nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.objectweb.asm.commons;

import java.util.HashMap;
import java.util.Map;

import org.objectweb.asm.Type;


A named method descriptor.

Author:Juozas Baliuka, Chris Nokleberg, Eric Bruneton
/**
 * A named method descriptor.
 * 
 * @author Juozas Baliuka
 * @author Chris Nokleberg
 * @author Eric Bruneton
 */
public class Method {

    
The method name.

/**
     * The method name.
     */
    private final String name;

    
The method descriptor.

/**
     * The method descriptor.
     */
    private final String desc;

    
Maps primitive Java type names to their descriptors.

/**
     * Maps primitive Java type names to their descriptors.
     */
    private static final Map<String, String> DESCRIPTORS;

    static {
        DESCRIPTORS = new HashMap<String, String>();
        DESCRIPTORS.put("void", "V");
        DESCRIPTORS.put("byte", "B");
        DESCRIPTORS.put("char", "C");
        DESCRIPTORS.put("double", "D");
        DESCRIPTORS.put("float", "F");
        DESCRIPTORS.put("int", "I");
        DESCRIPTORS.put("long", "J");
        DESCRIPTORS.put("short", "S");
        DESCRIPTORS.put("boolean", "Z");
    }

    
Creates a new Method. 
Params:
  • name – 
           the method's name.
  • desc – 
           the method's descriptor.
/**
     * Creates a new {@link Method}.
     * 
     * @param name
     *            the method's name.
     * @param desc
     *            the method's descriptor.
     */
    public Method(final String name, final String desc) {
        this.name = name;
        this.desc = desc;
    }

    
Creates a new Method. 
Params:
  • name – 
           the method's name.
  • returnType – 
           the method's return type.
  • argumentTypes – 
           the method's argument types.
/**
     * Creates a new {@link Method}.
     * 
     * @param name
     *            the method's name.
     * @param returnType
     *            the method's return type.
     * @param argumentTypes
     *            the method's argument types.
     */
    public Method(final String name, final Type returnType,
            final Type[] argumentTypes) {
        this(name, Type.getMethodDescriptor(returnType, argumentTypes));
    }

    
Creates a new Method. 
Params:
  • m – 
           a java.lang.reflect method descriptor
Returns:a Method corresponding to the given Java method declaration.
/**
     * Creates a new {@link Method}.
     * 
     * @param m
     *            a java.lang.reflect method descriptor
     * @return a {@link Method} corresponding to the given Java method
     *         declaration.
     */
    public static Method getMethod(java.lang.reflect.Method m) {
        return new Method(m.getName(), Type.getMethodDescriptor(m));
    }

    
Creates a new Method. 
Params:
  • c – 
           a java.lang.reflect constructor descriptor
Returns:a Method corresponding to the given Java constructor declaration.
/**
     * Creates a new {@link Method}.
     * 
     * @param c
     *            a java.lang.reflect constructor descriptor
     * @return a {@link Method} corresponding to the given Java constructor
     *         declaration.
     */
    public static Method getMethod(java.lang.reflect.Constructor<?> c) {
        return new Method("<init>", Type.getConstructorDescriptor(c));
    }

    
Returns a Method corresponding to the given Java method declaration. 
Params:
  • method – 
           a Java method declaration, without argument names, of the form
           "returnType name (argumentType1, ... argumentTypeN)", where
           the types are in plain Java (e.g. "int", "float",
           "java.util.List", ...). Classes of the java.lang package can
           be specified by their unqualified name; all other classes
           names must be fully qualified.
Throws:
Returns:a Method corresponding to the given Java method declaration.
/**
     * Returns a {@link Method} corresponding to the given Java method
     * declaration.
     * 
     * @param method
     *            a Java method declaration, without argument names, of the form
     *            "returnType name (argumentType1, ... argumentTypeN)", where
     *            the types are in plain Java (e.g. "int", "float",
     *            "java.util.List", ...). Classes of the java.lang package can
     *            be specified by their unqualified name; all other classes
     *            names must be fully qualified.
     * @return a {@link Method} corresponding to the given Java method
     *         declaration.
     * @throws IllegalArgumentException
     *             if <code>method</code> could not get parsed.
     */
    public static Method getMethod(final String method)
            throws IllegalArgumentException {
        return getMethod(method, false);
    }

    
Returns a Method corresponding to the given Java method declaration. 
Params:
  • method – 
           a Java method declaration, without argument names, of the form
           "returnType name (argumentType1, ... argumentTypeN)", where
           the types are in plain Java (e.g. "int", "float",
           "java.util.List", ...). Classes of the java.lang package may
           be specified by their unqualified name, depending on the
           defaultPackage argument; all other classes names must be fully
           qualified.
  • defaultPackage – 
           true if unqualified class names belong to the default package,
           or false if they correspond to java.lang classes. For instance
           "Object" means "Object" if this option is true, or
           "java.lang.Object" otherwise.
Throws:
Returns:a Method corresponding to the given Java method declaration.
/**
     * Returns a {@link Method} corresponding to the given Java method
     * declaration.
     * 
     * @param method
     *            a Java method declaration, without argument names, of the form
     *            "returnType name (argumentType1, ... argumentTypeN)", where
     *            the types are in plain Java (e.g. "int", "float",
     *            "java.util.List", ...). Classes of the java.lang package may
     *            be specified by their unqualified name, depending on the
     *            defaultPackage argument; all other classes names must be fully
     *            qualified.
     * @param defaultPackage
     *            true if unqualified class names belong to the default package,
     *            or false if they correspond to java.lang classes. For instance
     *            "Object" means "Object" if this option is true, or
     *            "java.lang.Object" otherwise.
     * @return a {@link Method} corresponding to the given Java method
     *         declaration.
     * @throws IllegalArgumentException
     *             if <code>method</code> could not get parsed.
     */
    public static Method getMethod(final String method,
            final boolean defaultPackage) throws IllegalArgumentException {
        int space = method.indexOf(' ');
        int start = method.indexOf('(', space) + 1;
        int end = method.indexOf(')', start);
        if (space == -1 || start == -1 || end == -1) {
            throw new IllegalArgumentException();
        }
        String returnType = method.substring(0, space);
        String methodName = method.substring(space + 1, start - 1).trim();
        StringBuilder sb = new StringBuilder();
        sb.append('(');
        int p;
        do {
            String s;
            p = method.indexOf(',', start);
            if (p == -1) {
                s = map(method.substring(start, end).trim(), defaultPackage);
            } else {
                s = map(method.substring(start, p).trim(), defaultPackage);
                start = p + 1;
            }
            sb.append(s);
        } while (p != -1);
        sb.append(')');
        sb.append(map(returnType, defaultPackage));
        return new Method(methodName, sb.toString());
    }

    private static String map(final String type, final boolean defaultPackage) {
        if ("".equals(type)) {
            return type;
        }

        StringBuilder sb = new StringBuilder();
        int index = 0;
        while ((index = type.indexOf("[]", index) + 1) > 0) {
            sb.append('[');
        }

        String t = type.substring(0, type.length() - sb.length() * 2);
        String desc = DESCRIPTORS.get(t);
        if (desc != null) {
            sb.append(desc);
        } else {
            sb.append('L');
            if (t.indexOf('.') < 0) {
                if (!defaultPackage) {
                    sb.append("java/lang/");
                }
                sb.append(t);
            } else {
                sb.append(t.replace('.', '/'));
            }
            sb.append(';');
        }
        return sb.toString();
    }

    
Returns the name of the method described by this object.

Returns:the name of the method described by this object.
/**
     * Returns the name of the method described by this object.
     * 
     * @return the name of the method described by this object.
     */
    public String getName() {
        return name;
    }

    
Returns the descriptor of the method described by this object.

Returns:the descriptor of the method described by this object.
/**
     * Returns the descriptor of the method described by this object.
     * 
     * @return the descriptor of the method described by this object.
     */
    public String getDescriptor() {
        return desc;
    }

    
Returns the return type of the method described by this object.

Returns:the return type of the method described by this object.
/**
     * Returns the return type of the method described by this object.
     * 
     * @return the return type of the method described by this object.
     */
    public Type getReturnType() {
        return Type.getReturnType(desc);
    }

    
Returns the argument types of the method described by this object.

Returns:the argument types of the method described by this object.
/**
     * Returns the argument types of the method described by this object.
     * 
     * @return the argument types of the method described by this object.
     */
    public Type[] getArgumentTypes() {
        return Type.getArgumentTypes(desc);
    }

    @Override
    public String toString() {
        return name + desc;
    }

    @Override
    public boolean equals(final Object o) {
        if (!(o instanceof Method)) {
            return false;
        }
        Method other = (Method) o;
        return name.equals(other.name) && desc.equals(other.desc);
    }

    @Override
    public int hashCode() {
        return name.hashCode() ^ desc.hashCode();
    }
}